A sliding bearing of a cylindrical shape which bearing is adapted to support a rotation shaft through a lubricant film, comprising a plurality of fine grooves juxtaposed on an inner peripheral face of said sliding bearing in a circumferential direction of the bearing, each of said grooves extending from a backward position of a minimum lubricant film thickness portion at which the lubricant film becomes minimum in thickness on the rotation of said shaft, to a forward position of said minimum lubricant film thickness portion.